Achillion Pharmaceuticals, Inc. (NASDAQ:ACHN): Piper recommends that investors buy Achillion (NASDAQ:ACHN) on any weakness following its presentations of data at EASL, as the firm believes that data from Abbott Pharmaceuticals (NYSE:ABT) on its HCV treatment are impressive and validates Achillion’s potential future HCV treatment.The firm views Achillion as a likely takeover target and maintains an Overweight rating on the stock.